DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Response to Amendment
This is a final office action in response to Applicant’s remarks filed on 12/29/2025. Claims 1-5 and 8-18 are presented for examination.
The 35 U.S.C. § 103 rejections in the previous office action are maintained.
Response to Arguments
Applicant's arguments filed 12/29/2025 have been fully considered but they are not persuasive.
Applicant argues Predtechenskiy is not prior art under 35 U.S.C. § 102(a)(2).
The Examiner notes that “In certain circumstances, references cited to show a universal fact need not be available as prior art before the effective filing date of applicant’s claimed invention. In re Wilson, 311 F.2d 266, 135 USPQ 442 (CCPA 1962). Such facts include the characteristics and properties of a material or a scientific truism” (MPEP 2124). The rejection relies on Predtechenskiy to show material properties of single-walled carbon nanotubes and therefore the reference need not be available as prior art.
Applicant argues that a person of ordinary skill in the art would not have been motivated to combine Yachi and Kobashi to arrive at the claimed invention. Yachi is directed to an electrode mixture layer containing long fibrous carbon. Yachi teaches that the long fibrous carbons are carbon nanofibers having a straight and rigid structure and are present in the electrode mixture layer as individual fibrous strands. Kobashi is a study directed to categorizing the structures of carbon nanotubes rather than the carbon nanofibers disclosed in Yachi.
The Examiner respectfully disagrees. Though Yachi uses carbon nanofibers to form the fibrous carbon in example embodiments, Yachi teaches the fibrous carbon may instead be formed by single-walled carbon nanotubes ([0066]).
Applicant argues the rejection of claim 1 relies on improper hindsight to arrive at the selection of small-diameter carbon nanotubes because Kobashi teaches that large-diameter multi-walled carbon nanotubes are advantageous in electrodes due to their commercial availability and cost, while large-diameter single-walled and double-walled carbon nanotubes are advantageous because of their high specific surface area.
The Examiner respectfully disagrees. While Kobashi teaches the advantages of other forms of carbon nanotubes, a skilled artisan would be motivated to select small-diameter single-walled carbon nanotubes to form the fibrous carbon in Yachi because Kobashi teaches that carbon nanotubes with high crystallinity and high specific surface area, i.e., small-diameter single-walled carbon nanotubes, are suitable for use as carbon fibers or reinforcing conductive additives because their high crystallinity and specific surface area gives high conductivity and mechanical strength (p. 4046, c. 1, ll. 5-6 and 10-13; Figure 3).
Applicant argues a skilled artisan would have no reasonable expectation of success in arriving at the claimed invention including graphene, a carbon nanotube structure, and carbon black, because doing so would require trying numerous possible choices until arriving at a successful result. The data in the specification illustrates that the electrodes of Comparative Examples 1-3, each of which omits one of the claimed conductive materials, had remarkably worse properties when compared to the electrode of Example 1 including all of the claimed conductive materials.
The Examiner respectfully disagrees. A skilled artisan would not require undue experimentation to arrive at an electrode including graphene, a carbon nanotube structure, and carbon black because Chen teaches the use of a conductive agent comprising graphene, a carbon nanotube structure, and carbon black.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1, 5, 8-11, and 13-18 are rejected under 35 U.S.C. 103 as being unpatentable over Yachi (US 2017/0098822 A1) in view of Chen (CN-106711453-A; the rejections below refer to the machine translation mailed 06/04/2024) and Kobashi (Classification of commercialized carbon nanotubes into three general categories as a guide for applications, 2019), as evidenced by Predtechenskiy (US 2022/0325080 A1).
Regarding claims 1 and 18, Yachi discloses an electrode ([0001]) comprising an electrode active material layer (electrode mixture layer, [0010]), the electrode active material layer comprising an electrode active material and a conductive agent (carbon based conductive agent, [0010]), the conductive agent comprising: a plurality of carbon structures (fibrous carbon, [0010]); and carbon black ([0099]), wherein the plurality of carbon structures (fibrous carbon) form a conductive network structure in the electrode active material (mixture) layer (three-dimensional dispersion of fibrous carbon forms a conductive path to reduce a resistance of the electrode mixture layer, [0077]), and wherein the conductive network structure is provided by the plurality of carbon structures (fibrous carbon) connected to each other (conductive path in which fibers of the fibrous carbon are in contact with each other, [0133]) and connecting between the electrode active material (active material is in contact with the conductive paths, [0220], FIG. 29).
Yachi teaches that the conductive agent may further comprise other carbon-based conductive materials, including graphene ([0099]), but does not disclose a specific embodiment in which the conductive agent comprises graphene, carbon structures, and carbon black.
Chen discloses an electrode comprising an electrode active material layer (positive electrode material pole piece, Fig. 4, [0050]), the electrode active material layer comprising an electrode active material (6, Fig. 4, [0050]) and a conductive agent, the conductive agent comprising: graphene (5, Fig. 4, [0050]); a carbon nanotube structure (4, Fig. 4, [0050]); and carbon black (7, Fig. 4, [0050]). A person having ordinary skill in the art before the effective filing date of the invention would have found it obvious to have added graphene to the conductive agent of Yachi because Chen teaches that a conductive agent comprising graphene, carbon nanotubes, and carbon black can improve conductivity by forming a three-dimensional conductive network of points, lines, and surfaces ([0064]).
Yachi discloses that the carbon structures (fibrous carbon) may be formed of single-walled (monolayer) carbon nanotubes ([0066]) and that the carbon structures preferably are linear ([0090]), but uses carbon fibers in example embodiments. Yachi in view of Chen does not disclose wherein each carbon structure is a carbon nanotube structure including single-walled carbon nanotube units bonded side by side in parallel with each other in a single plane.
Kobashi teaches that industrially used small-diameter single-walled carbon nanotubes form carbon nanotube structures including single-walled carbon nanotube units arranged side by side in parallel with each other in a single plane (small-diameter nanotubes have aligned fibrous structure, p. 4044 c. 1 ll. 2-5; small-diameter nanotubes are straight and form closely packed bundles, p. 4045 c. 1 ll. 5-7; see right side of Figure 1 on p. 4044 and left side of Figure 2 on p. 4045). A person having ordinary skill in the art before the effective filing date of the invention would have found it obvious to have used a carbon nanotube structure including single-walled carbon nanotube units arranged in side by side in parallel with each other in a single plane in the electrode of Yachi in view of Chen because Kobashi teaches that such carbon nanotube structures are suitable for use as carbon fibers or reinforcing conductive additives because their high crystallinity and specific surface area gives high conductivity and mechanical strength (p. 4046, c. 1, ll. 5-6 and 10-13; Figure 3).
Yachi in view of Chen and Kobashi does not disclose wherein the carbon nanotube structures include 2 to 5,000 single-walled nanotubes units bonded side by side in parallel with each other in a single plane.
Predtechenskiy evidences single-walled carbon units in bundles are bonded with one another due to Van der Waals forces and that the diameter and length of the bundles corresponds to the number of nanotube units forming the bundle ([0048]). Yachi in view of Chen and Kobashi is considered to meet the limitation “wherein the carbon nanotube structures include 2 to 5,000 single-walled nanotubes units bonded in parallel with each other” since Yachi teaches carbon structures having similar lengths and diameters to those of the instant application (length range of “10 µm or more” [0087] overlaps claimed range of “1 µm to 500 µm” in claim 8 of the instant application, diameter range of “less than 1000 nm” [0093] overlaps claimed range of “2 nm to 200 nm” in claim 10 of the instant application) and Kobashi teaches bundled single-walled carbon nanotubes (p. 4045 c. 1 ll. 5-7). Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established [MPEP § 2112.01].
Regarding claim 5, Yachi in view of Chen and Kobashi teaches the electrode of claim 1, but does not disclose wherein the graphene is included in an amount of 0.01 wt% to 1.0 wt% in the electrode active material layer.
Yachi teaches that the carbon-based conductive agent is included in 0.5 wt% to 20 wt% of the electrode active material layer ([0151]) and that the fibrous carbon corresponding to the carbon nanotube structure of the claimed invention constitutes 10% to 100% by mass of the conductive agent ([0099]), allowing for up to 18 wt% of graphene and carbon black in the active material layer.
A person having ordinary skill in the art before the effective filing date of the invention would have found it obvious to have included the graphene in an amount of 0.01 wt% to 1.0 wt% in the electrode active material layer of Yachi in view of Chen and Kobashi because Chen teaches that an effective conductive network can be formed when graphene is included in this amount (Chen: Embodiment 1, [0028]-[0033]; the conductive slurry representing 2 wt% of the electrode active material layer contains 30g carbon nanotubes, 70g graphene, 25g carbon black, 25g polymers, and 850g solvent; the graphene is therefore included in the electrode active material layer in an amount of 0.14 wt% to 0.93 wt% depending on the amount of solvent remaining in the prepared active material layer).
Regarding claim 8, Yachi in view of Chen and Kobashi teaches the electrode of claim 1, wherein the plurality of carbon nanotube structures (fibrous carbon) has an average length of 1 µm to 500 µm (Yachi: overlapping ranges of “10 µm or more,” preferably “10 to 100 µm,” more preferably “12 to 80 µm” and still more preferably “15 to 70 µm” [0087] establish a prima facie case of obviousness [MPEP § 2144.05(I)]).
Regarding claim 9, Yachi in view of Chen and Kobashi teaches the electrode of claim 1, wherein the plurality of carbon nanotube structures have an average length of 10 µm to 70 µm (Yachi: 15 to 70 µm [0087]).
Regarding claim 10, Yachi in view of Chen and Kobashi teaches the electrode of claim 1, wherein the plurality of carbon nanotube structures have an average diameter of 2 nm to 200 nm (Yachi: overlapping ranges of less than 1000 nm, preferably 50 to 900 nm, more preferably 100 to 600 nm, still more preferably 150 to 500 nm, and particularly preferably 200 to 400 nm [0093] establish a prima facie case of obviousness [MPEP § 2144.05(I)]).
Regarding claim 11, Yachi in view of Chen and Kobashi teaches the electrode of claim 1, wherein the plurality of carbon nanotube structures have an average diameter of 50 nm to 120 nm (Yachi: overlapping ranges of less than 1000 nm, preferably 50 to 900 nm, and more preferably 100 to 600 nm [0093] establish a prima facie case of obviousness [MPEP § 2144.05(I)]).
Regarding claim 13, Yachi in view of Chen and Kobashi teaches the electrode of claim 1, wherein the carbon black is contained in the electrode active material layer in an amount of 0.01 wt% to 1 wt% (Yachi: 1% by mass in Example 7, [0192]).
Alternatively, Yachi in view of Chen and Kobashi does not disclose a content of the carbon black in the electrode active material layer when the conductive agent comprises both graphene and carbon black.
Yachi teaches that the carbon-based conductive agent is included in 0.5 wt% to 20 wt% of the electrode active material layer ([0151]) and that the fibrous carbon corresponding to the carbon nanotube structure of the claimed invention constitutes 10% to 100% by mass of the conductive agent ([0099]), allowing for up to 18 wt% of graphene and carbon black in the active material layer.
A person having ordinary skill in the art before the effective filing date of the invention would have found it obvious to have included the carbon black in an amount of 0.01 wt% to 1.0 wt% in the electrode active material layer of Yachi in view of Chen and Kobashi because Chen teaches that an effective conductive network can be formed when carbon black is included in this amount (Chen: Embodiment 1, [0028]-[0033]; the conductive slurry representing 2 wt% of the electrode active material layer contains 30g carbon nanotubes, 70g graphene, 25g carbon black, 25g polymers, and 850g solvent; the carbon black is therefore included in the electrode active material layer in an amount of 0.05 wt% to 0.33 wt% depending on the amount of solvent remaining in the prepared active material layer).
Regarding claim 14, Yachi in view of Chen and Kobashi teaches the electrode of claim 1, but does not disclose wherein the weight ratio of the graphene, the plurality of carbon nanotube structures, and the carbon black is 0.01 to 3:0.01 to 0.5:0.1 to 10.
Yachi teaches that a weight ratio of the carbon nanotube structures to the graphene and carbon black is 10:1 to 0:1 (fibrous carbon constitutes 10% to 100% by mass of the conductive agent [0099]).
A person having ordinary skill in the art before the effective filing date of the invention would have found it obvious to have formed the electrode of Yachi in view of Chen and Kobashi such that a weight ratio of the plurality of carbon nanotube structures, and the carbon black is 0.01 to 3:0.01 to 0.5:0.1 to 10 because Chen teaches that an effective conductive network can be formed when the materials are included in this ratio (Chen: Embodiment 1 includes graphene, carbon nanotubes, and carbon black in a weight ratio of 1.2:0.5:0.42 [0031]).
Regarding claim 15, Yachi in view of Chen and Kobashi teaches the electrode of claim 1, wherein each carbon nanotube structure includes 50 to 4,000 single-walled carbon nanotube units bonded to each other (Kobashi teaches single-walled carbon nanotube bundles, p. 4045 c. 1 ll. 5-7; Predtechenskiy evidences the diameter and length of the bundles corresponds to the number of nanotube units forming the bundle [0048]; Yachi teaches lengths [0087] and diameters [0093] overlapping those of the instant claims as discussed in the rejection of claim 1). Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established [MPEP § 2112.01].
Regarding claim 16, Yachi in view of Chen and Kobashi teaches a secondary battery comprising the electrode of claim 1 (Yachi: [0002]).
Regarding claim 17, Yachi in view of Chen and Kobashi teaches the electrode of claim 1, wherein the plurality of carbon nanotube structures are contained in the active material layer in an amount of 0.01 wt% to 0.5 wt% (Yachi: overlapping range of 0.5 to 3.0% by mass, [0127] establishes a prima facie case of obviousness [MPEP § 2144.05(I)]).
Alternatively, Yachi in view of Chen and Kobashi does not disclose a content of the carbon nanotube structure in the electrode active material layer when the conductive agent also comprises both graphene and carbon black.
A person having ordinary skill in the art before the effective filing date of the invention would have found it obvious to have included the carbon black in an amount of 0.01 wt% to 0.5 wt% in the electrode active material layer of Yachi in view of Chen and Kobashi because Chen teaches that an effective conductive network can be formed when carbon nanotube structure is included in this amount (Chen: Embodiment 1, [0028]-[0033]; the conductive slurry representing 2 wt% of the electrode active material layer contains 30g carbon nanotubes, 70g graphene, 25g carbon black, 25g polymers, and 850g solvent; the carbon nanotube structure is therefore included in the electrode active material layer in an amount of 0.06 wt% to 0.4 wt% depending on the amount of solvent remaining in the prepared active material layer).
Claims 2 and 4 are rejected under 35 U.S.C. 103 as being unpatentable over Yachi (US 2017/0098822 A1) in view of Chen (CN-106711453-A) and Kobashi (Classification of commercialized carbon nanotubes into three general categories as a guide for applications, 2019) and as evidenced by Predtechenskiy (US 2022/0325080 A1), as applied to claim 1 above, and further in view of Shi (Choice for graphene as conductive additive for cathode of lithium-ion batteries, 2019, cited 06/04/2024).
Regarding claim 2, Yachi in view of Chen and Kobashi teaches the electrode of claim 1 but does not disclose wherein the graphene has an average length of 0.1 µm to 100 µm.
Shi teaches an electrode comprising an electrode active material layer, the active material layer comprising an electrode active material (LiCoO2, sec. 2.3 on p. 20) and graphene (sec. 2.1 on p. 20) having average lengths between 3 and 30 µm (¶1 of sec. 3, p. 20 bridging p. 21). It would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to have optimized the average length of the graphene in the electrode of Yachi in view of Chen and Kobashi, including to a range corresponding to “0.1 µm to 100 µm,” because Shi teaches that the graphene should be large enough to cover active materials and form a conductive bridge, but not so large as to restrict ion conductivity in the electrode (Fig. 3, ¶4 of sec. 3 on p. 22, ¶7 of sec. 3 on p. 23). It has been held that where the general conditions of the claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art [MPEP § 2144.05(II)A].
Regarding claim 4, Yachi in view of Chen and Kobashi teaches the electrode of claim 1 but does not disclose wherein the graphene has a BET specific surface area of 100 m2/g to 500 m2/g.
Shi teaches an electrode comprising an electrode active material layer, the active material layer comprising an electrode active material (LiCoO2, sec. 2.3 on p. 20) and graphene (sec. 2.1 on p. 20). It would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to have optimized the BET specific surface area of the graphene in the electrode of Yachi in view of Chen and Kobashi, including to a range corresponding to “100 m2/g to 500 m2/g,” because Shi teaches that the graphene should have a surface area large enough to effectively form 3D conductive networks connecting active material particles and other conductive additives, but not so high as to have poor dispersibility or lower the volumetric energy density of the electrode (¶5 of sec. 1 on p. 20).
Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over Yachi (US 2017/0098822 A1) in view of Chen (CN-106711453-A) and Kobashi (Classification of commercialized carbon nanotubes into three general categories as a guide for applications, 2019) and as evidenced by Predtechenskiy (US 2022/0325080 A1), as applied to claim 1 above, and further in view of Wang (Liquid-exfoliated graphene as highly efficient conductive additives for cathodes in lithium ion batteries, 2019, cited 06/04/2024).
Regarding claim 3, Yachi in view of Chen and Kobashi teaches the electrode of claim 1 but does not disclose wherein the graphene has an average thickness of 0.3 nm to 300 nm.
Wang teaches an electrode comprising an active material layer, the active material layer comprising an electrode active material (LFP, LFP, LCO, and NCM, sec. 2.2 on p. 157) and graphene (sec. 2.2 on p. 157). It would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to have used graphene with an average thickness of 1.3 nm, which reads on the claim range of “0.3 nm to 300 nm,” in the electrode of Yachi in view of Chen and Kobashi because Wang teaches graphene prepared by jet cavitation having a thickness of 1.3 nm (¶1 of sec. 3 on p. 157) has high conductivity and is scalable, low-cost, and environmentally friendly (sec. 4 on p. 161).
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Yachi (US 2017/0098822 A1) in view of Chen (CN-106711453-A) and Kobashi (Classification of commercialized carbon nanotubes into three general categories as a guide for applications, 2019) as evidenced by Predtechenskiy (US 2022/0325080 A1), as applied to claim 1 above, and as evidenced by Denka (Denka Black Product Information, 2019).
Regarding claim 12, Yachi in view of Chen and Kobashi teaches the electrode of claim 1, wherein the carbon black has an average particle diameter (D50) of 1 nm to 500 nm (Yachi: carbon black is Denka Black manufactured by Denka Company Limited [0192]; Denka evidences that the average particle diameter of Denka black is 35 nm to 48 nm, List of Physical Properties, p. 7).
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any extension fee pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/C.C.D./Examiner, Art Unit 1723 /TIFFANY LEGETTE/Supervisory Patent Examiner, Art Unit 1723